A Limulus reagent (also called a lysate reagent) is a reagent which comprises a horseshoe crab amoebocyte lysate as the main component and is used for the detection and measurement of an endotoxin (hereinafter referred to as “Et”) and a (1→3)-β-glucan (hereinafter referred to as “BG”). Since Et and BG have reactivity with a Limulus reagent, when the Limulus reagent and there substances contact with one another, a cascade reaction in which various factors in the Limulus reagent are concerned (hereinafter referred to as “Limulus reaction”) is induced, so that these substances can be detected and measured by detecting this reaction.
On the other hand, it is known that a lipoarabinomannan (hereinafter referred to as “LAM”) is a cell wall component specific to acid-fast bacteria (e.g., tubercle bacillus, etc.).
Patent Reference 1 discloses a Limulus reaction-activating substance which is physically different from Et and BG, an inactivation method thereof, a measuring method thereof and the like. However, this substance is completely different from LAM as is described later, and there is no disclosure or suggestion that LAM has reactivity with a Limulus reagent.    Patent Reference 1: JP-A-10-185924